1. Field of the Invention
The invention relates to an input output device, and more particularly to an input output device for mixed-voltage tolerant.
2. Description of the Related Art
With the development of technology, integrated circuits (ICs) are widely used electronic products. Each of the ICs comprises a large amount of transistors. To reduce the size and power consumption of the ICs, the thickness of the gate oxide of the transistors must been reduced. However, peripheral devices still require higher voltage (such as 5V). Thus, if transistors comprising the thin gate oxide receive the higher voltage, the gate oxide reliability of the transistors will not be maintained.